1. Field of the Invention
The present invention relates to a caster and, more particularly, to a caster having improved vibratory characteristics.
2. Description of Related Art
Traditionally, casters have been incorporated onto a moveable object to create a transport system that can be moved from one location to another. For example, dollies and carts have been outfitted with casters and used to transport heavy items such as boxes, supplies, tools, and equipment. Selection of an appropriate caster for a particular application is determined by various factors, including load weight, operating environment, and floor condition.
A conventional transport system incorporating casters generates noise as the transport system moves over a surface due to vibration caused by excessive movement of components in the caster assembly. In certain environments, such as hospitals, long-term care facilities, schools, and offices, excessive noise is unacceptable. Accordingly, the Occupational Safety and Health Administration (OSHA) has developed regulations setting forth acceptable noise exposure levels for various workplace environments. Moreover, noise generated by conventional transport systems restricts the time certain activities can be conducted. For example, cleaning carts using conventional casters can disrupt classes in schools and meetings in offices if cleaning takes place during the day. Similarly, such cleaning carts can disrupt sleeping patients in hospitals and care facilities if cleaning takes place at night.
In an effort to reduce noise generated by conventional transport systems, devices such as sound absorbers and vibration dampers (e.g., lead base tape) have been employed. Such devices can be installed on the transport system to absorb vibration and/or deaden its travel. Additionally, some conventional casters utilize a softer tread material to absorb vibration. One disadvantage of such devices is that they do not sufficiently reduce noise generated by the transport system. Another disadvantage of such devices is that they merely absorb vibration and/or deaden its travel but do not eliminate the source of the vibration.